With patent extension up for grabs, Shire agrees to test Vyvanse in preschoolers

To hear Shire ($SHPG) tell it, there aren't many adequate and well-controlled drug studies in preschool-aged children with ADHD. But never fear, the company says: It's agreed to a written request by the FDA to investigate its ADHD drug Vyvanse in children aged 4 to 5, with a potential 6-month exclusivity boost for the drug on the line.

The Irish drugmaker is currently working on designing three trials to make up the pediatric clinical trial program, which it expects to begin in the first half of 2015. It pegs the prevalence of ADHD in the preschool population at between 3% and 5%, and only a small number of those children respond well to behavioral therapy, it said.

"Additional efficacy and safety data will help clinicians and parents make informed treatment decisions for preschool-age children with ADHD," company R&D head Philip Vickers said in a statement.

So what's in it for Shire? Besides the potential market expansion that would come with broadening Vyvanse's label, if Shire meets the FDA's requirements with its submission, it'll snag a 6-month patent exclusivity extension on the drug under the Best Pharmaceuticals for Children Act.

While Vyvanse already has its IP shield set through 2023, extra protection for its lead drug certainly can't hurt. In the meantime, the company has been working to diversify its portfolio beyond its flagship ADHD products, making moves in particular toward the rare disease arena. To that end, it beat out Big Pharma competitors like Sanofi ($SNY) to pick up rare-disease drugmaker ViroPharma for $4.2 billion last year.

But its expansion into the fast-growing field has made it all the more appealing as a target itself, analysts have said, and it may need to bulk up a bit more if it wants to dodge some acquisition-hungry predators.

"If they want to stay independent, then going on a bit of a shopping spree makes it harder for another entity to go after them," Piper Jaffray analyst David Amsellem told Bloomberg last week. "They will be approached. They probably have been approached."